The present invention relates to the field of linear generators of electrical current, in which the current is generated by the movement of the moving part of an induction system with respect to a fixed part thereof.
More particularly, the invention relates to the type of generator in which the pistons of the internal combustion engine are free and complete their return stroke under the action of a system of springs.
An example of this type of generator is described in patent application PCT/EP95/02054 (Rigazzi).
In the present state of the art, the permanent magnets forming the said induction system are movable, being integral with the piston or pistons of the internal combustion part, and the coils forming the other part of the system are fixed coaxially with respect to the magnets.
However, this arrangement of the parts has the drawback that, in order to absorb the mechanical power generated by the internal combustion part, it is necessary to use a quantity of magnets having a significantly large mass, with all the disadvantages arising from the fact that it is then necessary to move this mass rapidly to produce electrical energy. As far as the inventor is aware, the use of moving coils has not even been considered as yet, because of the problem of fatigue fracture of the output wires of the coils due to their reciprocating movement.
However, the inventor of the present invention has perceived that the prerequisites for the provision of the technical arrangements required to overcome this drawback are already present in a generator of the type described above.
This is because, by a novel arrangement of the parts, in which the return springs of the pistons are used as output conductors for the current flowing in the coils, the coils can be moved without the use of moving parts which break as a result of fatigue.
This is because the aforesaid springs are designed to withstand long periods of use without being adversely affected by the stresses to which they are subjected.
Furthermore, in the generators in question, the springs operate in a region having a temperature close to the ambient temperature, and therefore they are not damaged in any way by the slight increase in their temperature caused by the current flowing through them.
The inventor has therefore made use of the elements described above to devise the solution according to the present invention, which consists of a linear generator as described in the precharacterizing clause of the attached claim 1, characterized by what is disclosed in the characterizing clause of the said claim.
A preferred embodiment of the linear generator according to the invention will now be described, with the proviso that this example is not binding or limiting with respect to other different embodiments which can be produced by a person skilled in the art on the basis of the content of the aforesaid claim 1.